There is documentation to build, install and test this add-in. Source
code is released under the same license as OpenTURNS, and is commented so
that adding new functions should be pretty straightforward. It has been
tested with Excel 2010 and 2013, but should work with any version >= 2007.

Your feedback is very welcome, please use github tracker if there are any
issues, and let us know if you write your own XLL.

Using the new cross-compilation framework for the modules, I built the first binary version of the openturns-mixmod module for Windows. It is compatible with the official 1.0 release of OpenTURNS and should run both on 32bits and 64bits versions of Windows, from XP to seven.